Fuel-injection system



April 3; 1928; 1,664,609

L. O. FRENCH` FUEL INJECTION SYSTEM Filed July 28, 1924 fessure fa/ya.

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" tage inthe system Patented Apr. 3, 1928.

LOUIS 0. FRENCH, F MILWAUKEE, WISCONSIN.

FUEL-INJECTION SYSTEM. v

Application :tiled July 28, 1924. Serial No. 728,805.

The invention relates to fuel injection systems.

The general object o f the invention is to provide a fuel injection s stem for injectiontype engines in which t e quantity of fuel and the time it is furnished to the engine may be accurately controlled.

In systemsof this kind 't is not always feasible from the standpoint of efficient operation and maintenance to operate the fuel injection valve electrically. From the operation standpoint it will be appreciated that in some instances there is a disadvantage in providing electrical energy for operating the fuel injection valve when both the fuel pressure and the varying pressures in the cylinder have to lbek taken into consideration.

From a maintenance standpoint it is to be v noted that in order to operate a valve electrically with a minimum expenditure of energy, the adjustment of the valve relative to its operating magnet should be carefully maintained so as to keep the air gap at a proper working efficiency. Such adjustments for efficient electrical operation may not be readily maintained in the hands of unskilled-'persons if applied to a fuel injection valve because, asis quite frequently the case, this valve has to be taken apart for cleaning, resetting or r'e rinding, or because of clogging of the nozz e by deposits from the cylinder, with a consequent necessity for readjustment. The object, therefore, of this invention, is to provide a fuel injection system in which an electrically-operated control valve, distinct from the outlet valve or fuel injector valve, will operate for long periods of time without any attention and with a minimum expenditure of-electrical energy for its efficient operation-.and will lcontrol the operation of the 4fuel injector.

A further object of this invention is to provide a fuel injectiony system for' multi- .cylinder engines in which the fuel, at sub,- stantially constant pressure in a supply pipe, is furnished to automatically-operable fuel injection valves whose operations are under the control of electrically-operated control valves.

Where the fuel injection valve is so arranged tvith reference to the combustion chamber and the cylinder headY that it is liable to become highly heated during the operation of the engine, there is an advaniereinafter described in the separate electrically-operated control valve since the possible/danger of the overheating or destruction of the insulation of the energizing coil is thereby prevented.

The invention further consists in the sev-J eral features hereinafter set forth and more particularly defined by claims at the conclusion hereof.

.In the drawings: Fig. 1 is a view partly in diagrammatic form, o a fuel injection system embodying the invention, parts being shown in section;

Fig. 2 is a vertical sectional view through one of the control valves shown in Fig. 1;

Fig..3 1s a vertical sectional view through the switch mechanism used in the system;

Fig. 4 is a detail sectional view taken on the line 4--4 of Fi 3;

Fig. 5 is a .detail sectional view taken on the broken line 5-5 of Fig. 4.

Referring to Fig. 1, the numeral 6 designates a fuel suppl tank, 7 a pump connected with theta by a pipe 8 and driven by. the engine being sup lied with fuel and being preferably a dou le-actin pump or one which will insure a steady ow of fuel to the pressure pipeV or line 9. It will be understood that a suitable fuel strainer is provided in the tank or incorporated in the pump or ma be used in the supply line for the pump. be maintained substantially constant and of a predetermined value in any of the wellknown ways and for thepurpose of illustration I show a pressure valve of any suitable construction loaded to the desired amount to maintain a pressure head of fuel in the line 9 of the desired value. From the valve 10 some of the fuel may pass through a pipe 11 back to the supply tank. Leading from the discharge pipe 9 are branch pipes 12 and 13 which conduct the fuel to the control devices 14 and then bypipes 15 to the fuel injectors, of the automatic type and one of which 16 is shown in section in connection with the pipe 12. As here shown the iiijector 16 includes a casing 17 mounted in the head 18 of one of the cylinders of the engine and having a discharge nozzle 19 at its lower end through which fuel passes to the combustion chamber or a chamber in communication with the combustion chainber, the passage of fuel through a duct 20, communicating with pipe 15, to said nozzle being controlled by a check valve 21 norhe pressure in the line 9 may mally held closed a spring` 22 and the ressure on the hea of the valve, the valve eilig opened by the fuel pressure. With the present system each cylinder of a multicylinder engine has its injector supplied with fuel from abranch pipe of the pressure line and the supp 'y to each injector is controlled l by the control device 14.

- 23 and closes oil' its lower end, andis clamped thereto by an annular nut 28 in threaded enga ment with the lower end o f said casing. ghis valve assembly or unit includes a valve guide member 29, a valve seat member 30,-.a valve 31 and a spring 32 said member 30 having an annular flange 30 seating against the lower endv of the casing 23 and held thereagainst inv a fuel-tight manner by the inwardly extending iiange 33 of the nut 28.

The valve guide member 29 is in the form of a tubular cap, littin for the most art close to the inner wall o the casing and vaving ports 34, its up er end leading to the chamber 35 formed above it in the casing 23, said cap having a depending stem guide portion 36, an interiorly-threaded portion 37 and a smooth bore portion 38.

The valve seat member 30 is in the form of a screw-plug havin a threaded portion 39 engaging the threared portion 37 of the member and a cylindrical portion 40 fitting closely inA the bore 38 so as to center said plug` relative to the axis of the guide porit whichis tapped at its lower end 41 for a pipe couplin 42 and is of reduced diallieter at 43 and as a valve seat 44- at the outlet of the part 43. v

The valve 31 is preferably'in the form of a needle having its stem guided inthe bore of the'portion`36, a renewable tip 45 fitting into the lower end of the stem and a springseat-flange 46 adjacent the tip, the spring 32 being interposed between said flange and the upper end of member 29. The upper .end of the stem is threaded and a disk 47 of magnetic material formed integral with or se cured to a sleeve-nut 48 is adjustably mounted on said stem and held in adjusted position by a locknut 49. Apin 50 of non-ma netic material and mounted either in t e disk or, as shown, in the -core 24, 'ust prevents direct contact between vthe d core to prevent any chance of freezing, The parts 23, 29 and 30 are of non-magnetic material and the spring 32 may also be of non-magnetic material. It will be noted tion 36. This plug has a passage throughl isk and moved as a unit from the casing 23, if

necessary.

o A tapped outlet 51` from the chamber y35 'I is adapted to receive a pi fitting for con,l nesting a pipe, such ast e pipe 15, to the fuel injector, which pipe ma be made short tov minimize the amount o fuel held betweenthe chamber 35 and outlet of the casing 17, and the casing 23 may be directly attached to or formed 'as a part of the. injector casing, so long as the control valve 3l 1s distinct from the valve 21, and preferably so that the injector valve 21 can be removed without disturbing the adjustment of the valve 31.

With this construct-ion 12 or 13 and slightly in excess of `this pres-y sure. Then when the magnet 25 becomes energized the core 24 attracts the disky 47 the loa-d imposedl by the spring 32 on the valve 31 is such as and raises the valve off its seat, allowing I fuel to pa from the pressure supply to the injector. The electrical energy necessary to raise the valve is that necessary to overcome l the excess of spring pressure over the fuel pressure and friction of the parts. The

clearance between the disk 47 and the core should be very small so as to ermit. the4 magnet to operate at best eiliciency. For the usual automotive type engines the total lift be more than a sixtyo f the valve need not fourth to one-hundredth of an inch or less, and the passage 43 should be as small as pos` sible so. as to reduce the amount of sprin pressure required to close the valve for the .particular fuel pressure chosen. ,f

yFrom the foregoing it will be noted'that m5' the time of opening the control valve 31 1 j the duration of its opening will corr'e-` .o

and

lilo

spondingly effect the injector valve 21 and t ereby determine the theamount of fuel that is to be furnished `to the engine.' length of time determined byv time of injection and 'n l' The time of opening andliu the valve lstaysfopen is the time and ,duration of energization of the coil 27;y ofthe electro-v l magnet, and this is effected byfswitch mechanism in the circuit supplying the coilwith electrical energy.

Switch mechanismsuitable pose and especially gines, is shown in wherein the numeral `for mult-icylinder'- 'en- 52 designatesa tubular support upon which Ithe base plate 53 of the.

switch casing is rotatably mounted, said plate having a bearing on a flanged vcollar 54 secured to the support, as by a threadedr connection therewith. A shaft 55, driven by cam member 56 slidably the enginehas a keyed thereto iuV any suitable manner, said cam causing'the 'o ning and closing of the fxthe magnets of the conff switch for each o Figs. 3 lto 5, inclusive,

forv `this purs lil trol devices. One of said switches is shown element57 carrying the contact 58 and the lined element 59 having lthe contact 60 adjustably mounted thereon.

The switch element 57 isin the form of a two-armed lever preferably formed of sheet metal having a channel section except for its ends,'and is pivoted on a pin or bolt l,6l carried by the ears 62 of a mounting-plate 63 secured to the base-plate-53. One arm of I thisv lever carries the Contact 5 8 and the, other pass Wit-hin is apertured to receive a ball 64, of metal or libre, which ball is held between said arm and a. plate 65 turned over the` upper end vof said arm andvriyetcd. to. the arm beneath the ball. This ball is held in operative relation with the cam by a flat curved spring 66 whose free end lits between the sides and bears against the web of the cliannel'of element 57 and whose-other end fits into a pocket or 'recess-67 formed inthe plate 63.

rlhe fixed .element 59 preferably includes a contact-Carr ing block 68 'welded orbrazed to the late-ra extensions of a sheet meta-l channel support 69 within which a part'of.

the contact-carrying arm ofthe element 57 works. This support 69 has outwardlyextending ears`70 through which screws 71 insulated bushings 72 and through mounting-plate `63 into the plate 53, said ears being insulated' from the plate 63 v by insulation material 73. The lower part titl toward the cani and cause engagement of the of the web of the channel 69 is out out, as at 7e.;- so thatjthe element 59 is entirely inbsalatedl from the plates 531and 63. A cover 75 of insulating material encloses the switch mechanism 'and has threaded bushings 76 therein. through which contact screws 77 pass i of the fixed' into engagement with the back contact support 69, said screws having the usual .terminal 'binding nuts 78 thereon for the current supply wires. `These' screws 77', by theirengagement withthe supports 69, may also serve to clamp or holdtliecover 75 inv position on the plate'53. v The removal ot the cover gives ready access to theentii'e mechanism Vof each switch unit.

The cani 56 fis cylindrical .except for a iattened'tapered face .portion 79 milled or otherwise 'formed on itywith' one side preferably parallel with the axis of the cam and the .other 'side tape-red.l l Thestraight or parallel side is preferably the; advancing side., -When the ball; 64' engages the cylindrical surface ci the ,cam the contacts 58,' and 60 are held apart and when'the flatv iacc- 7 9 registers with-tlieball'ft the neces` sary' clearance is provided, for the lever 57 under the action ofthe: spring 66 to swing cantacts 58 and (ifteclose the circuit. Since the datiface 79 is tapered, the varyingv of the positionfofthis acerelative tothe ball will vary the time during which the cir cuit is closed. Also, since the case 53 carry-k in detail and'ineludes the pivoted switchr in? the switch or switches can be turned re ative to the cain by manual or governor operationof an arm 8O secured to the plate 53, the time the switch or switches start to close can be varied.

The cam .56 may be moved up and down to var its position by either governor or manua ly-operated means. As shown, the

cam isnormally held in a position for an working in slots (not shown) in the support 52, and .engaged by the forked ends of a lever 8 8 carried by a shaft 89 journalled in a sectional casing secured to said' support, said shaft extending outside of the casing andv provided on its exposed end` with an arm 91 which may be manually or governor.v actuated. Thus, by the angular adjustment of the switch or switches relative to the cam` and the longitudinal adjustment of the cam, the time and duration of energizationot the control device or devices may be effect-ed and thus the time of initiating the injection and the amount of fuel injected may be varied to vsuit the power requirements of the engine. It will also be noted that as the switch unit is radially disposed and its plane of operationradial relative to the cam axis, a number of these units may be compactly arranged about the cam for a multicylinder engine.

The magnets receive current from a hattery 92 energy, one terminal of the battery being shown grounded, as on the engine, in Fig. l, and the other terminal connected by conductors 93 with one end of the coil of each magnet 25. The other end of the -coil of each magnet is connected by a conductor 94 with the fixed contact 60 of the switch mechanism through connection with the screw 77, andthe movable contact 58 is grounded" metal plate 53, sup-port 52 to the through engine.,

Cut-outswitches 95 in the conducof fuel to the engine be provided in each magnet circuit for energizing the magnet toY facilitate initial priming 'of the systema such as to provide an .overload or priming; 'char e to assist in Astarting the engine, after whici vthe Cain is moved to position to or other suitable source ofelectricalors 94, when opened, preventfurther supply f A switch 96may also The initial position o' the :cam may be ist `furnish -full or reduced lload charges ci? r 'inet to the'v engine.

While the operation of the electroinagnet valve 31 is controlled'by the switch mecha1 mism, its'operation constitutes what may be means for supplying said pipe with fuel,

' 't,electromagnetically-operated valve to there-v `branch conduits' from said supply termed the sole means for controlling the operation of the injection or outlet valve 21 as distinguished from those systems in which the'fuelr injector valve is itself mechanically or electrically controlled or operated.

I desire it to be understood that this invention is not to be limited to any particular form or arrangement of parts except in so far as such limitations are specified in the claims. f

What I claim as my invention:

1. In a fuel injection system, the combination with a multicylinder engine, of a supply pipe containing fuel at injection pressure, means for supplying said pipe with fuel,

pipe leading to' each cylinder of the engine, a fuelpressure-operated injector controlling .the passage of fuel from each branch conduit to the cylinder. supplied thereby, an electromagnetically-operated valve in each branch conduit and constituting the sole means for controlling the operation of the fuel injector associated with that conduit, a source of electrical current, and circuit control means operated by the engine, supply of current to the operating magnet of each electromagnetically-operated valve. .v 2. In a fuel injection system, the combination with a multicylinder engine, of a supply pipe containing 'fuel at injection pressure,

branch conduits from said supply pipe leading to each cylinder of the engine, a fuelpressure-operated injector controlling the passage of fuelfrom each branch conduit to the cylinder K supplied thereby, an electromagnetically-operated valve in each branch conduit and constituting the sole means forcontrolling the operation of the fuel injector associated with that conduit, a source ofelectrical current, and adjustable circuit con- "trol means operated by the engine, for conl trolling the time and duration of current supply, to the operating vmagnet of each bycontrol the time and duration of operation of said fuel injector.

tion with theffengine and an injector for supplying fuel thereto, fofa, supply conduit vfor said'injeetr containing fue under pressure,

an electromagnetically-operated valve in said conduit controllingthe supply of fuel to said injector, said valve including a casing, an

velectroniagnet having its core forming a closure for one end of said casing, anda valve for controlling the.

3. In av fuel injection system, the combina-` unit extending into the other end-of said casing and clamped theretocomprising a needlevalve provided with an armature for said magnet, a guide member for the stem of said valve, av valve-seat member secured to said guide member, and a spring interposed between said guide member and valve.

4. In a fuel injection system, the combination with the enUine cylinder, of a fuel injector supplying fuel to the cylinder and having a spring-closed outlet valve opening toward the cylinder, a supply conduit containing fuel under substantially constant pressure and leading to said valve, an electromagnetically-operated valve in said supply conduit constituting the sole means for con-- valve, and engine-controlled circuit control means controlling the operation of said electromagnetically-operated valve.

6. In a fuel injection system, the combination With the engine cylinder, "of a fuel injector supplying Iuel to the cylinder and having a spring-.closed outlet valve, a supply conduit containing fuel under pressure, a valve casing `connected to said conduit, a conduit connecting said valve casing with said fuel injector, a control valve in said casing controlling the passage of fuel to said second named conduit, a spring fornormally closing said valve a inst the fuel pressure in saidl supply con uit, saidl control valve being entirely enclosed Within said casing and moving` within, the fuel therein, an electro-magnet associated' with said control valve and adapted to exert an attractive force thereon to open it against the excess of spring pressure overthe pressure onlyof the fuel in said supply conduit, means for energizing said electro-magnet, and engine-controlled means for controlling the operation of said energizing means, said outletl valve depending for its openin of said control va ve.

In testimony whereof, I allix my signature.

solely upon the opening 10ftA 

